What was done
The authors analyzed a number of sediment properties and different types of geochemical data obtained from a core removed from the eastern Bransfield Basin just off the northern tip of the Antarctic Peninsula (61°58.9'S, 55°57.4'W), including grain size, total organic carbon content, magnetic susceptibility, biogenic silica content, ²¹⁰Pb geochronology and radiocarbon (¹⁴C) age.

What was learned
The authors' data clearly depict, as they clearly state, the presence of the "Little Ice Age and Medieval Warm period, together with preceding climatic events of similar intensity and duration."

What it means
The authors say that "two of the most significant climatic events during the late Holocene are the Little Ice Age (LIA) and Medieval Warm Period (MWP), both of which occurred globally (Lamb, 1965; Grove, 1988)," noting further that "evidence of the LIA has been found in several studies of Antarctic marine sediments (Leventer and Dunbar, 1988; Leventer et al., 1996; Domack et al., 2000)."  To this list of scientific journal articles documenting the existence of the LIA in Antarctica can now be added the authors' own paper, which also demonstrates the presence of the MWP in Antarctica, as well as earlier cold and warm periods of similar intensity and duration.  Hence, it is (or at least should be) getting more and more difficult for climate alarmists to continue claiming that these several-hundred-year cold and warm periods were confined to lands bordering on the North Atlantic Ocean.  They clearly were global; and they clearly demonstrate the reality of the millennial-scale climatic oscillation that is manifest in the post-1850 warming of the world that climate alarmists misconstrue as having been caused by the concomitant rise in the air's CO2 content.

References
Domack, E.W., Leventer, A., Dunbar, R., Taylor, F., Brachfeld, S. and Sjunneskog, C.  2000.  Chronology of the Palmer Deep site, Antarctic Peninsula: A Holocene palaeoenvironmental reference for the circum-Antarctic.  The Holocene 11: 1-9.

Grove, J.M.  1988.  The Little Ice Age.  Cambridge University Press, Cambridge, UK.

Keigwin, L.D.  1996.  The Little Ice Age and Medieval Warm Period in the Sargasso Sea.  Science 274: 1504-1508.

Lamb, H.H.  1965.  The early medieval warm epoch and its sequel.  Palaeogeography, Palaeoclimatology, Palaeoecology 1: 13-37.

Leventer, A. and Dunbar, R.B.  1988.  Recent diatom record of McMurdo Sound, Antarctica: Implications for the history of sea-ice extent.  Paleoceanography 3: 373-386.

Leventer, A., Domack, E.W., Ishman, S.E., Brachfeld, S., McClennen, C.E. and Manley, P.  1996.  Productivity cycles of 200-300 years in the Antarctic Peninsula region: Understanding linkage among the sun, atmosphere, oceans, sea ice, and biota.  Geological Society of America Bulletin 108: 1626-1644.